1. Field of the Invention
This invention relates in general to electrically powered mowers and relates more particularly to such a mower with a dual motor drive system to power the cutting blades and accessories.
2. Prior Art
In the conventional reel mower, each cutting unit is powered by its own reel motor. The reel motor is mounted to one side of the frame of the cutting unit, and drives the reel assembly through a coupling. In an electrically powered mower, the electric motor needed to supply sufficient torque to the reel is quite large, typically 4.0" in diameter and between 6 to 8" long. The large size of this side mounted reel motor may create problems with ground clearance on undulating terrain, clearance between the reels, and clearance between the motor and the fringe cut (the grass bordering the green). For example, since the height of the grass on the green is typically 0.10" to 0.18" and the height of the grass in the area around the green is 0.30" to 0.75", mowing the edge of the green causes the side mounted reel motor to overhang the fringe area adjacent the green. The large reel motor may not clear the taller grass in the fringe area, thus causing undesirable compaction.
A side mounted motor typically also has problems with side clearance. Since the side mounted motor usually extends from the side of the reel by around 6" to 8" inches, if the side mounted motor is mounted on the inside of one of the front reels, the clearance between the two front reels is required to be at least the length of the side mounted motor, thereby limiting closer placement of the reels. Similarly, if the side mounted motor is on the outside of one of the forward reels, it extends an extra 6" to 8" from the side of the reel and thus the entire mower, preventing the mower from making a close cut near bushes, fences, or other obstructions.
Another problem with a side mounted reel motor is that it must be counterbalanced so that the reel will be level and provide an even cut. Prior art greens mowers use a torsion spring counterbalance system, or simply add weight to the other side of the reel to counterbalance the weight of the motor. The total weight of the reel-motor system is increased, causing undesirable compaction of the grass.
Finally, when a reel on a side mounted mower needs service, the side mounted motors must be removed from the reel in order to access and to service the reel.
One prior art mower embodying the above-mentioned drawbacks is described in U.S. Pat. No. 5,406,778 to Lamb.
There is a need, therefore, for a reel mower drive system that does not have the above drawbacks.